May 29, 2022
DMR from Las Vegas to the Mexican border in San Diego
By Earl Lizardi WB6AMT
The following frequency compilation was created by Tony WB6MIE and road tested by Earl WB6AMT on October 19, 2019.
The main objective was to create one zone ( Labeled “I-15” ) of frequencies in my XPR655o portable that would allow me to maintain constant contact with stations here in the Las Vegas valley while on the road to the Mexican border in San Diego.
The trick of course was to get all the repeaters that were geographically in line with our route to the Mexican border on I-15.
By programming the frequencies of DMR repeaters with the Talk-Group SoCal (TG 31066) as they were encountered along the trip, it made it very easy to keep constant contact back to “Base” (Vegas) simply by changing frequency on the radio to the next repeater as I drove in and out of the different repeater’s coverage areas.
A note about Talk-Groups:
On a BrandMeister repeater, talkgroups can be static (permanently
activated by the administrator) or dynamic (temporarily activated by a
user).
The repeater administrators determine how their repeaters are configured.
Some allow only specific static talkgroups to be used on each time slot.
Others allow users to activate dynamic talkgroups, in which case, the
convention is:
-Users are allowed to activate dynamic wide-area talkgroups on time slot 1.
-Time slot 2 is normally used for static local talkgroups.
When you activate a dynamic talkgroup on a repeater’s time slot by keying up, it remains activated on the repeater as long as you continue transmitting on it. When you stop transmitting, it automatically gets dropped from the repeater after a period of inactivity, typically 15 minutes.
At times the Vegas station did have to refresh the Dynamic-timer for the SoCal talk group on the Low Potosi repeater if we didn’t talk after a 15 minute break.
Time slot 2 is used for static local talkgroups.
What I did not expect was the excellent overlapping of coverage from several repeaters along the trip.
Not being familiar with the actual coverage areas of many repeaters along the route, the good old repeater acknowledgement tones helped me know if I was good into the next repeater.
I was able to maintain solid communications well into the next coverage area.
As I reached the outer boundary of a repeater ( slight break-up) that was my que to switch to the next repeater.
This worked perfectly except for the Heaps repeater, which was off the air that day, or may not have been setup to accept Dynamic Talk Groups.
We picked up Quartzite within a few minutes and continued with communications all the way to the Mexican border in San Diego.
This is the order repeater data was programmed :
Channel Name | Time Slot | Color Code |Rx Freq | Tx Freq | Contact name |Admit Criteria |In Call Criteria
1 DMR LoPot SoCal, 1 1 448.2750 443.2750 SoCal CC Free Always
2 DMR Turq SoCal , 1 2 448.1625 443.1325 SoCal CC Free Always
3 DMR RdMn SoCal , 1 1 448.1375 443.1375 SoCal CC Free Always
4 DMR Heaps SoCal, 1 1 447.5200 442.5200 SoCal CC Free Always
5 DMR Qsite SoCal. 1 2 448.1500 443.1500 SoCal CC Free Always
6 DMR Bxspg SoCal, 1 1 446.0500 441.0500 SoCal CC Free Always
7 DMR Snst SoCal , 1 1 446.0375 441.0375 SoCal CC Free Always
8 DMR Sntgo SoCal, 1 1 448.1375 443.1375 SoCal CC Free Always
9 DMR Elsn SoCal, 2 1 445.7200 440.7200 SoCal CC Free Always
10 DMR Palmr SoCal, 2 1 445.8600 440.8600 SoCal CC Free Always
11 DMR Wdsn SoCal, 2 1 445.9600 440.9600 SoCal CC Free Always
12 DMR Otay SoCal, 2 3 447.2600 442.2600 Socal CC Free Always
What was great about this programming scheme was that when it was time to head back to Las Vegas, all I had to do was change channels back one step at a time in reverse until we were back in Las Vegas.
Just like you would do to plan a vacation trip with gas stops along the way, a little pre-planning for repeater freqs ahead of time made this trip the perfect travel companion.